CVE-2021-3493

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

17/04/2021

Last modified:

19/02/2025

Description

The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 8.80 HIGH
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

8.80

Severity 3.x

HIGH

Vector 2.0

AV:L/AC:L/Au:N/C:C/I:C/A:C CVSS v2.0 Severity and Metrics:

Base Score: 7.20 HIGH
Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C

Attack Vector (AV): Local
Attack Complexity (AC): Low
Authentication (Au): None
Confidentiality (C): Complete
Integrity (I): Complete
Availability (A): Complete

Base Score 2.0

7.20

Severity 2.0

HIGH

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:o:canonical:ubuntu_linux:::::lts:::*		18.04 (excluding)
cpe:2.3:o:canonical:ubuntu_linux:::::lts:::*	18.04.1 (including)	20.04 (excluding)
cpe:2.3:o:canonical:ubuntu_linux:::::-:::*		20.10 (excluding)

To consult the complete list of CPE names with products and versions, see this page

CVE-2021-3493

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools